Offenders who have committed the most serious crimes have been locked up for a combined total of 390-and-a-half years in 2016.
The Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit was founded in April 2012, and this year took on 53 investigations.
Convictions this year include Operation Pargo, which saw rapist Stefan Padure sentenced to 12 years in prison on November 25.
Padure attacked a woman in Hemel Hempstead in March, and it is recommended he be deported after serving his sentence.
Another criminal jailed was John McAleer, who threw his girlfriend 45ft from a block of flats in Hemel in June last year.
He was handed a 15-year sentence for attempted murder with extended licence.
Detective Superintendent Karena Thomas, of the joint protective services command, said: “The cases the unit deal with can be extremely harrowing and have a profound impact on victims, their families and in some cases the wider community.
“Our main focus will always be to do the right thing for those affected by these horrendous crimes.
“Our specially trained officers and staff work around the clock to secure justice, ensuring some of the most dangerous offenders in our counties are put before the courts.”
The tri-force unit is made up of more than 170 staff who investigate all major crimes across the three counties. The offences they deal with include murder, manslaughter, stranger rape, and kidnap and extortion as well as cold case (historic) offences. Staff include crime scene co-ordinators,family liaison support, digital media investigators and analysts.
At any one time the teams are investigating up to 50 cases.