In 1993, Grigoryan left the secondary school with teaching in Russian № 122 named after A. Blok (Yerevan).

In 1997–2001, Grigoryan studied at the Prosecution and Investigative department of the special faculty of the Military University of the Ministry of Defence (the Russian Federation). As an external student, Grigoryan graduated with honours [with the gold medal] from the mentioned department.

In 2006–2009, he studied at the adjunct faculty of Military University of the Ministry of Defense (the Russian Federation). Grigoryan defended his PhD thesis and was awarded the degree of Candidate of Sciences in Law [PhD in Law].

In 2013, Grigoryan entered the extramural [part-time] doctorate of the Military University of the Ministry of Defense (the Russian Federation) and worked on his doctoral thesis. In 2017, the successful pre-defence of the mentioned thesis took place.

In 2021, Grigoryan defended his doctoral thesis at the academic council of the Russian-Armenian (Slavonic) University in the Republic of Armenia. Grigoryan was awarded the academic degree of Doctor of Law.

In 2001–2024, Grigoryan worked in the institutes of the prosecution, the Investigative Service of the Ministry of Defence, the Investigative committee and the institutions of the judicial system of the Republic of Armenia.

In 2001–2006, Grigoryan served at the Garrisons of the Military Prosecutor’s office of the Republic of Armenia in Yerevan, Hadrut and Martakert as a trainee investigator, then as an investigator and thereafter as a senior investigator. For 2 years, Grigoryan was a member of different investigative groups of the Investigative department for cases of special importance [major case squads] of the Military Prosecutor’s office of the Republic of Armenia.

2009–2010 the Senior Investigator at the Department of Supervision, Methodology and Analysis of the Investigative Service of the Ministry of Defense of the Republic of Armenia.

2010–2011 the Head of the II (Hadrut) Garrison Investigative department of the Investigative Service of the Ministry of Defense of the Republic of Armenia (commander of № № 55292 military unit of the Ministry of Defense of the Republic of Armenia).

2011–2014 Deputy Head of the Investigative Service of the Ministry of Defense of the Republic of Armenia. He administered the activities of the Garrison Investigative departments in Stepanakert, Hadrut, Martakert, and later in Eghegnadzor and Goris as well (deputy commander of № 55555 military unit of the Ministry of Defense of the Republic of Armenia).

2014–2015 Deputy Head of the General Military Investigative department of the Investigative committee of the Republic of Armenia.

2015–2018 Grigoryan was a Deputy Chairman of the Investigative committee of the Republic of Armenia; the Head of the General Military Investigative department.

2018–2021 the Head of the Investigative committee of the Republic of Armenia.

In 2022–2024, Grigoryan was a scientist member of the Supreme Judicial Council.

In 2024, the National Assembly of the Republic of Armenia elected Grigoryan a judge of the Criminal Chamber of the Court of Cassation of the Republic of Armenia,

Grigoryan is the Third Class State Councillor of Justice and the Honoured Investigator.

In 1994–1996, he served in the Armed Forces of the Republic of Armenia.

In 2017–2018, Grigoryan was the head of the qualification board of the Investigative committee of the Republic of Armenia.

In 2006, June 15 by the decree № 230 of the Prosecutor General of the Republic of Armenia, Grigoryan was awarded the First Class Lawyer rank as an incentive for solving two premeditated murders in a generally dangerous manner in conditions of obscurity.

Grigoryan has got many awards for the conscientious performance of his official duties in the course of his work. He was awarded 22 medals, 1 state award, 4 badges, and 4 commemorative medals.

Grigoryan is the author of more than 50 scientific articles published both in Armenian and international journals. He is also the author of 3 monographs which relate to topical issues of criminal and international law, and those of criminal proceedings and criminology.

Grigoryan is a member of the Specialised Council 063 on Jurisprudence of the Higher Attestation Commission of the Republic of Armenia at the Russian-Armenian (Slavonic) University; the specialisation is ԺԲ 00.06 «International Law».

Grigoryan is fluent in Armenian, English, and Russian.