Some of the damage caused by activist Joseph Harris. Photograph: Northamptonshire Police/PA
Joseph Harris, 26, a doctor of molecular biology, was jailed for three years at Northampton Crown Court. He is the first person to be convicted under new legislation designed to tackle harassment and threats from animal rights activists.
The court heard how Harris - who has published papers on pancreatic cancer - came under professional pressure to take part in animal experiments, putting him in "an increasing moral dilemma". His girlfriend also left him, disapproving of his work.
Harris attacked three companies linked to the Cambridgeshire animal research firm Huntingdon Life Sciences during December and January. None were directly involved in testing, but supplied scientific equipment, building materials and refrigeration servicing.
He broke into premises and attacked equipment, slashed tyres and glued locks, also spray-painting animal rights slogans on walls and vehicles, causing more than £25,000 of damage in total. The court heard that the first attack, on a Nottingham refrigeration company, took place on the day Harris was awarded his PhD.
Rebecca Trowler, defending, said that Harris's work at Queen's Medical Centre in Nottingham on a treatment for pancreatic cancer was linked to experiments on animals.
"Inevitably, over time as his career progressed he was coming under pressure to participate in these experiments," she said. "The girlfriend who he was involved with had ended the relationship because of his continued work in the field of medical research because she disapproved of this activity.
"This put him in an increasing moral dilemma. Essentially he came to a crisis point and he took a very, very stupid decision. He has a genuine concern for the world - in particular his belief that the experimentation on animals which causes suffering is never justified - notwithstanding the progress it can produce for the human race."
Harris pleaded guilty to three charges under the Serious Organised Crime and Police Act, brought in by the government last year.
Jailing the scientist, Judge Ian Alexander said it had brought him "great discomfort in seeing you before the court, having thrown so much away".
The judge added: "I am sorry that your conviction and the sentence I impose will seriously damage what was a very promising career.
"It may well be that your future inability to continue your research into gastro-intestinal cancer will be a great loss to those who suffer that disease.
"The seriousness and objective of your offences must be marked both as a punishment and deterrent to others."
The court was told that Harris did not belong to any specific animal rights group, although he daubed the initials ALF - Animal Liberation Front - in one premises.
He was arrested at the scene of his third attack, at a builders' merchants in Northampton. DNA tests and chemical analysis of spray-paint cans found with him connected Harris to the other two incidents.